Abrasive tool



March 4, 1941.

G. BONwlTT ABRAsIv'E Toon Filed Feb. 9, 1940 INVENTOR: @asav on WMZ A TTORNEY Patented Mar. 4, 1941 UNITED STATES 2,233,469 I l I ABRASIVE TOOL- l `(lustav Bonwitt, NewYork, N. Y. Application February 9, 1940, Serial No. 318,107`

6 Claims.

For carrying-out grinding; lapping, truingand similar operations abrasive bodies are used which are produced by loosely wrapping abrasive sheet materials e. g. sand paper, emery paper, emerycloth and the like around blocks of' suitable shape ing is' impracticable'. and that". the" thusvcreatedt abrasive bodies becomev inoperative after a much:

shorter time than this'wa's to be expectedfrom the natural duration and wear-resistance of 'the' used abrasive materials.

It is an object of this invention to create b-y the application of abrasivelv sheets atool of which practically the entire abrasive surface mayv bey utilized for grinding, lapping, truing and similar operations.

It is a further object of this invention to produce an abrasive tool of the mentioned type of` which the abrasive sheet can' be Very easily replaced with a minimum of timeand manipula-1 tion.

Among other novel features ofthe present invention reference is made to an improved means for securing the abrasive sheet on its holder or carrier in such a manner that an individualy displacement upon the carrier is fully` prevented' and that a continuously plain surface of` the operative part of the tool is insured at any time.

It is a further object of the invention to maintain and to prolungate as much as possible the operability and usability of the abrasive sheets without reduction of their eiciency.

It is also an object of the invention to reliably connect the operative part of the tool with the handle in a cheap, most simple and eflicient manner. v

With the above and other objects in view the invention consists of an improved abrasive tool consisting of an abrasive sheet covered carrier and in the form and construction of its several parts as will be hereinafter more fully described and illustrated in the accompanying drawing.

In the drawing, wherein I have shown several practical and simple embodiments of the invention and in which similar reference characters designate corresponding parts,

(CII. 51-187) Fig. 1 to Fig. 4fare'vertical' sectional Viewsy ofseveral embodiments of the present abrasive tool,

Fig. 5 isa horizontal sectional view taken along theline 5-5fof Fig. 1, f

Fig. 6 is a plan view of the lower endv of the 5 tool shown in Fig. 4, I

Fig. 7 is aplan view of the upper end of the tool shownl in'Fig. 2.`

The toolsh'own in Fig. 1 comprises a carrier I for the abrasive sheet' which consists of a longi- 10 tudin'al barA of' suitable materiale. g. wood having-.arectangular cross section as shown in Fig. 5. Longitudinal grooves I0 extend over the two oppo's'itefshort sides: of theicarrier bar I. An emery cloth sheet 2. is wrapped around said bar I in 15 preferably* such a manner. that its edges overlap each. other within the. grooves.

For fastening the emergy sheet or sand paper or the like'- uponV the carrier' I a U-shaped twoshank clamp-rodi I6 is provided of which the 20:

Shanks 3 are articulated by a link 4, which is located in the web part of the U-shaped rod. It is advisable to slightly bend off the shanks 3 as shown in dotted lines in Fig. 1. 'Ihe thus created resiliency of the Shanks serves to improvethe 5"" hold ofthe abrasive sheets upon the carrier I. A hollowhandle 5 is provided having at its upper end an inner shoulder 1.

'I'lieshanks have at thev lower ends two ilanges 30. 6. The carrier I is connected with the handle 5` by*means of a ller piece 8 whichis screwed into theN hollow handle and presses the ilanges 6 against the shoulder 1.

The replacement of a worn-off abrasive sheet 35. is eiected in the following manner:

The filler piece 8 isr screwed out of the handle 5. The carrier I including the clamp rod IB is pushed through and out of the hollow handle in the direction of the arrow. The clamp-rod I6 is 40 opened whereby the shanks 3 emerge from the grooves I0 of the carrier I. The abrasive sheet is removed from the carrier I and a new sheet is wrapped around the same. The shanks 3 of the clamp rod I6 are pressed into the grooves 5. The thus covered carrier I including clamp rod IB is pushed through the hollow handle in a direction opposite to the one indicated by the arrow until the flanges Ii strike against the shoulder 1. By now screwing the ller piece 8 into the hollow 50 handle 5 the flanges and the shoulder 'I are pressed together and the carrier I is rmly secured in the handle.

In the embodiment of the invention shown in Fig. 2 a solid handle 5 is used. Two holes I2 are-55 bored into the handle. The clamping equipment for the abrasive sheet consists in this form of the invention of two separate shanks 3 which full the same functions as the corresponding shanks of the embodiment of Fig. 2. The shanks are originally slightly bent in their longitudinal direction as shown by dotted lines.

In order to replace the abrasive sheet 2 the clamp IB is pulled out of the handle 5. The shanks 3 open themselves out on account of their resiliency whereby their hold on the abrasive sheet is loosened. Then the connecting plate I5 is taken off. The worn-ofi abrasive sheet 2 is replaced by a new, sheet. The shanks 3 are' pressed into the grooves I0, the carrier including clamp I6 is inserted in the holes I2 of the handle and the fastening plate I5 pushed over the upper free ends of the clamp shanks 3.

In the embodiment of the invention shownin Fig. 3 a two handle tool is shown. The construction and the form of the individual parts is similar to the form shown in Fig. 2 and the only difference consists therein that instead of the fastening plate I5 a second handle 5a is provided, which is pushed onto the upper ends of the Shanks 3.

According to the embodiment of the invention illustrated in Fig. 4 the holes vI2 of Fig. 2 are bored entirely through the handle 5. The clamp I6 consists of a single U-shaped rod. Carrier I Isupporting abrasive sheet 2 as Well as the clamp I6 are pushed through the holes I2 and a fastening plate I4 is pushed over their protruding free ends and immobilised onthe handle 5 by rotation of the plate I4 in the known manner.'

It is to be understood that in practice I reserve the right to exemplify my `present improvements in various other alternative embodiments and to adopt numerous modications in the form, conf struction and relative arrangement of the several elements as herein `described and as may fairly be considered as embraced within the spirit and scope of the appended claims.

1. In an abrasive tool comprising an elongated carrier for abrasive sheets, e. g. sand paper, emery paper, emery-cloth and the like, longitudinalrecesses on opposite sides of said carrier, an abrasive sheet detachably wrapped around said carrienwith its side edges overlapping each other within at least one of said grooves, clamping means adapted to be inserted in said recesses and to hold said abrasive sheet on said carrier, at least one detachable handle and means to secure within and to connect said clamping means and said carrier with said handle. A.

- 2'. An abrasive tool comprising an elongated carrier for abrasive sheets, longitudinal grooves on opposite sides of said carrier, at least onev ,carrier for abrasive sheets, longitudinal grooves on opposite sides of said carrier, at least one abrasive sheet detachably Wrapped around said carrier with its side edges overlapping each other in said grooves, a U`shaped clamp rod having two'slightly bentclamping shanks, said Shanks adapted to be inserted in said `grooves having flanges at theirlower ends, a hollow handle, inner shoulders within the upper end of said Vhollow handle and a connecting member to be inserted in `said hollow handle to press said flanges against said shoulders and-to connect with and secure saidclamp-rod and said carrier in said handle; 4. An abra-sive tool .comprising an elongatedv carrier for abrasive sheets, recesses on opposite Y sides of said carrier, at least one abrasive :sheet detachablywrapped around said carrier, clamping means to be inserted in said recesses and to I hold said abrasive sheet on said carrier, a handle and means to connect said clamping means and said carrier with said handle.

5. An abrasive tool comprising an elongated carrier for abrasive sheets,l longitudinal grooves on opposite sides of said carrier, at least one` abrasive sheet detachably wrapped around said carrier with the side edges overlapping each other in -said grooves, a U-shaped clamp rod hav` ing two slightly bent shanks, a handle, two holes in said handle for the insertion of said Shanks in said handle and a connecting plate adapted to connect said clamping shanks and to secure the same and said carrier in said handle. s

6. An abrasive tool comprising an elongated carrier for abrasive sheets, longitudinal grooves on opposite sides of said carrier, at leastv one abrasive sheet detachably wrapped around said carrier with the side edges overlapping each other within said grooves, a U-shaped clamping rod having two clamping shanks adapted to be in;` ser-ted into `said grooves and to hold said abrasive sheet on said carrier, a handle, two holes bored through said handle and adapted to receive said l clamping Shanks and means to connect said` clamping rods and said carrier with said handle.

. GUSTAV BONWITT. 

